Drip emitters are commonly used in irrigation systems to convert water flowing through a supply tube at a relatively high flow rate to a relatively low flow rate at the outlet of each emitter. Each drip emitter generally includes a housing defining a flow path that reduces high pressure water entering the drip emitter into relatively low pressure water exiting the drip emitter. Multiple drip emitters are commonly mounted on the inside or outside of a water supply tube. In one type of system, a large number of drip emitters are mounted at regular and predetermined intervals along the length of the supply tube to distribute water at precise points to surrounding land and vegetation. These emitters may either be mounted internally (i.e., in-line emitters) or externally (i.e., on-line or branch emitters). Some advantages to in-line emitters are that the emitter units are less susceptible to being knocked loose from the fluid carrying conduit and the conduit can be buried underground if desired (i.e., subsurface emitters) which further makes it difficult for the emitter to be inadvertently damaged (e.g., by way of being hit or kicked by a person, hit by a lawnmower or trimmer, etc.).
In addition to the advantages of in-line emitters, subsurface drip emitters provide numerous advantages over drip emitters located and installed above ground. First, they limit water loss due to runoff and evaporation and thereby provide significant savings in water consumption. Water may also be used more economically by directing it at precise locations of the root systems of plants or other desired subsurface locations.
Second, subsurface drip emitters provide convenience. They allow the user to irrigate the surrounding terrain at any time of day or night without restriction. For example, such emitters may be used to water park or school grounds at any desired time. Drip emitters located above ground, on the other hand, may be undesirable at parks and school grounds during daytime hours when children or other individuals are present.
Third, subsurface emitters are not easily vandalized, given their installation in a relatively inaccessible location, i.e., underground. Thus, use of such subsurface emitters results in reduced costs associated with replacing vandalized equipment and with monitoring for the occurrence of such vandalism. For instance, use of subsurface emitters may lessen the costs associated with maintenance of publicly accessible areas, such as parks, school grounds, and landscaping around commercial buildings and parking lots.
Fourth, the use of subsurface drip emitters can prevent the distribution of water to undesired terrain, such as roadways and walkways. More specifically, the use of subsurface drip emitters prevents undesirable “overspray.” In contrast, above-ground emitters often generate overspray that disturbs vehicles and/or pedestrians. The above-identified advantages are only illustrative; other advantages exist in connection with the use of subsurface drip emitters.
Although some advantages of subsurface emitters are described above, it would be desirable to provide an improved in-line drip emitter design that can be used in both subsurface and above ground applications. For both applications, there is a need to provide for a relatively constant water output from each of the emitters in the irrigation system. More specifically, it is desirable to provide pressure compensation so as to ensure that the flow rate of the first emitter in the system is substantially the same as the last emitter in the system. Without such flow rate compensation, the last emitter in a series of emitters will experience a greater pressure loss than the first. Such pressure loss results in the inefficient and wasteful use of water.
There is also a need in the irrigation industry to keep drip emitters for both subsurface and above ground applications from becoming obstructed, which results in insufficient water distribution and potential plant death. Obstruction of an emitter may result from the introduction of grit, debris, or other particulate matter from debris entering the emitter through the supply tube. It is therefore desirable to have an inlet and/or other structures that are of a design to deflect particles that might otherwise clog flow passages in the body of the emitter. The flow through area of the inlet, however, must also be large enough to allow proper functioning of the drip emitter.
It is also desirable to provide a drip emitter that minimizes parts and assembly as this will not only make the component less complicated to construct and likely save on material costs, but will also reduce the number of emitters that do not perform as desired due to misaligned parts, etc. Drip emitters are commonly formed of multi-piece components (e.g., two or more-piece housing structures with separate flexible diaphragms, etc.) that require individual manufacture of the various parts of the emitter and then assembly of the parts prior to mounting to the supply tube. Even slight misalignment of these components during assembly may result in a malfunctioning drip emitter. Thus, in addition to the above needs, it would be desirable to reduce the number of components required to make the emitter and the manufacturing steps and time it takes to create a finished product.
It is also desirable to provide a drip emitter that minimizes the amount of disturbance the emitter causes to the fluid flowing through the drip line or conduit to which the emitter is connected. Larger cylindrical emitters are available in the marketplace for in-line emitter applications, however, these emitters interfere with the flow of the fluid traveling through the drip line or tube and introduce more turbulence to the fluid or system due to the fact they cover and extend inward from the entire inner surface of the drip line or tube. The increased mass of the cylindrical unit and the fact it extends about the entire inner surface of the drip line or tube also increases the likelihood that the emitter will get clogged with grit or other particulates (which are more typically present at the wall portion of the tube than in the middle of the tube) and/or that the emitter itself will form a surface upon which grit or particulates will build-up on inside the drip line and slow the flow of fluid through the drip line or reduce the efficiency of this fluid flow. Thus, there is also a need to reduce the size of in-line emitters and improve the efficiency of the systems within which these items are mounted.
Lastly, it is also desirable to provide a drip line that can be buried sub-surface and/or under surface coverings such as bark or mulch without being interfered with by obstructions such as roots, grit, etc. Conventional emitters typically have difficulty in being used in at least sub-surface applications due to root obstruction that occurs from plants or vegetation growing toward the emitter creating an obstruction to the normal flow of fluid through the emitter. In the past, chemicals have been devised for use with sub-surface irrigation equipment to inhibit such root growth/interference, but these chemicals are either expensive to use or damaging to other materials used in the irrigation system (e.g., tubing, couplings, valves, the emitter itself, etc.).
Accordingly, it has been determined that the need exists for an improved in-line emitter and methods relating to same which overcomes the aforementioned limitations and which further provides capabilities, features and functions, not available in current bases and methods, and for an improved method for doing the same.
Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention.